8 coats of paint down, 1 disaster passed, 3 different types of roller used and the end is in sight.
Okay lesson #1 it really does need to be thinned 50%.
#2 you NEED a HIGH DENSITY foam roller. Not the thing that looks like a mattress pad. The proper roller is tapered at one end. Spend some time squeezing rollers and pick out the stiffest one. Do NOT use a fabric roller, it'll leave brick like patterns.
#3 if it doesn't feel right wipe it all off and start over. I almost left a bad coat on to sand off later figuring it would cost me 2 coats to do so. Thats dumb, if its going to be WORSE I should just clean and repaint, which is what I did.
#4 more prep work (ie better sanding) at each step will make for a better job. I was too slow to get into 400 grit and didn't spend enough time there. Thats okay, this is a 50 foot car. If your car wants to look better don't worry as much about painting, spend more time on prep.